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Even if you’ve been vaccinated, it’s important to keep masking up

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Can you spread COVID-19 after vaccination? Here’s what we know

by Kate Baggaley

December 28, 2020

On December 18, the U.S. Food and Drug Administration granted Moderna’s COVID-19 vaccine emergency use authorization. The vaccine is the second to win approval in the US, and the first doses were administered on Monday.

This milestone is impressive both because the vaccines from Moderna and Pfizer were developed at record-breaking speed and because they appear to be more than 90 percent effective (at least in clinical trials) at protecting people from developing symptomatic COVID-19. But one thing that isn’t clear yet is whether COVID-19 vaccines will also prevent vaccinated people from carrying the novel coronavirus without feeling sick and unwittingly spreading it to others. This means that for now, it’s important to keep wearing masks, socially distancing, and taking other precautionary measures even if you have been vaccinated.

“It would not be so far-fetched to have a vaccine that protects you from developing the worst COVID disease, but you could be infected and you could be spreading it [without] getting really sick,” says Jeffrey Bethony, a professor of microbiology, immunology, and tropical medicine at the George Washington University School of Medicine and Health Sciences who works on vaccines for parasitic diseases and HIV. “There is hope that they prevent transmission, but we simply don’t know enough about them yet.”

One reason that this novel virus—officially called SARS-CoV-2—has spread so rampantly is that people can be contagious several days before they feel ill, and in some cases never develop symptoms. Such a high rate of asymptomatic spread is “just not all that common in other infections,” says Susanna Naggie, an associate professor of medicine in the Duke University School of Medicine who specializes in infectious diseases. “With flu there is asymptomatic disease, but not at the level we see with SARS-CoV-2.” This makes it particularly important to understand whether COVID-19 vaccines will prevent asymptomatic infections, she says.

Many vaccines—including those for hepatitis A and B, measles, chickenpox, and human papillomavirus—do prevent people both from becoming ill and from passing the pathogen to others. “Generally, we believe that if you have a vaccine that prevents disease, you’re likely preventing infections as well, but you can’t assume that that’s 100 percent [the case],” Naggie says.

Some pathogens can infect and reproduce in vaccinated people for short periods of time without making them sick, including the bacteria that cause meningitis and pertussis, or whooping cough. This is also a problem for vaccines under development for parasitic illnesses such as malaria, schistosomiasis, and hookworm infection, Bethony says. “The vaccine protects people against the most serious clinical manifestations of the disease but it doesn’t entirely stop infection,” Bethony says. “You still might have a person who is mildly infected, and they’re still able to spread the disease.”

Whether an inoculation will prevent infection partly depends on the vaccine’s mechanism of action. Many COVID-19 vaccines, including those by Moderna and Pfizer, target the spike-shaped proteins on the surface of SARS-CoV-2 that help it bind to and enter host cells. “We’re talking about developing antibodies and immune response directly to the spike protein,” Naggie says. “So the hope would be that you could truly prevent infection.”

Several developers have reported early data hinting that their COVID-19 vaccines will reduce asymptomatic infections. During late-stage trials for the vaccine developed by the University of Oxford and AstraZeneca, some participants were given weekly COVID-19 tests. One group accidentally was given a low first dose of the vaccine followed by the intended full second dose. Asymptomatic infections were less common in this vaccinated group than they were among those who received a placebo. Researchers are still investigating why that low-dose group fared better than the full-dose group in that regard.

In Moderna’s clinical trials, researchers swabbed participants before they received each of their two doses of the vaccine. On December 15, the drugmaker reported that 38 volunteers who received the placebo tested positive without showing COVID-19 symptoms before their second dose, compared with only 14 from the group that received the vaccine.

“Presumably that means it also decreases the risk of transmission, although to prove that will take a lot more work,” Naggie says. “Maybe the vaccine completely prevents infection, or maybe it really shortens the period of infection and someone sheds for only a couple of days … these would all be very critical pieces to answer that.”

Investigating this question may become easier as at-home COVID-19 testing kits become more common. In follow-up clinical trials, researchers could ask people to swab themselves daily and track how often vaccinated people test positive and whether they pass the virus to other members of their household, Naggie says.

Several vaccine developers, including Moderna and Pfizer, are planning to test the blood of trial participants for antibodies that recognize a part of the virus that wasn’t targeted by the vaccine. Such antibodies would indicate whether a person became infected after being vaccinated.

Another way to find out how well COVID-19 vaccines prevent transmission is to monitor areas where vaccination is prevalent to see if infections also drop among the remaining unvaccinated people, Bethony says. This type of situation occurred after the first polio vaccine was introduced in 1955; the following year, scientists saw fewer cases even than they were expecting because enough kids had been immunized that the virus had trouble reaching those who hadn’t.

In the US, COVID-19 vaccines have only become available within the past several weeks and aren’t expected to be distributed to the general public before next spring. It’s going to be a while before we reach herd immunity. It’s also still unclear what percent of Americans need to be vaccinated for us to reach this stage as herd immunity depends on many factors including how quickly the virus spreads within various communities, and how effective the vaccines are at preventing the spread of the novel virus.

“We are just getting access to the vaccine and so for some months to come … we probably are still looking at questions about the role of the vaccine in transmission and the need to continue all these public health measures,” Naggie says. “For the time being, until we have adequate immunity in our communities and until we know better about transmission, the answer is yes.” So get vaccinated when you are able and keep masking up.

 

(POPULAR SCIENCE)

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31st night…Down Under

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The NYE scene at the Grand Reception Centre, in Melbourne

Despite the COVID-19 restrictions, the Voluntary Outreach Club (VOC) in Victoria, Australia, was able to hold a successful New Year’s Eve celebration, at The Grand Reception Centre, in Cathies Lane, Wantirna South.

In a venue that comfortably holds 800, the 200 guests (Covid restrictions), spanning three generations, had plenty of room to move around and dance to the array of fabulous music provided by the four bands – Replay 6, Ebony, Cloud 9 with Sonali, Redemption and All About That Brass. 

The drinks provided, they say, oiled the rusty feet of the guests, who were able to finally dress up and attend such an event after nine months of lockdown and restrictions. With plenty of room for dancing, the guests had a thoroughly enjoyable time. 

According to an insider, the sustenance of an antipasto platter, eastern and western smorgasbord, and the midnight milk rice and katta sambol, were simply delicious, not forgetting the fantastic service provided by Jude de Silva, AJ Senewiratne and The Grand staff.

The icing on the cake, I’m told, was the hugely generous sponsorship of the bands by Bert Ekenaike. This gesture boosted the coffers of the VOC, which helps 80 beneficiaries, in Sri Lanka, comprising singles and couples, by sending Rs. 3,000 to Rs. 3,500, per month, to each of these beneficiaries, and augmenting this sum, twice a year, in July and December, with a bonus of the same amounts.

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Fall armyworm:

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Strategies for effective management

by Prof. Rohan Rajapakse

Emeritus Professor of Entomology University of Ruhuna and former Executive Director Sri Lanka Council of Agriculture Research Policy

Fall armyworm Spodoptera frugiperda (Lepidoptera; Noctuidae), a quarantine pest, has been identified as a very destructive insect pest of Maize/Corn. This insect originated in Americas and invaded the African region in 2016 and was detected in India the following year and perhaps would have naturally migrated to Sri Lanka last year from India. Now, it is reported that FAW is present in all districts of Sri Lanka except Nuwara-Eliya and Jaffna. In winter in the USA the pest is found in Texas and Florida and subsequent summer when it gets warmed up, the pest migrates up to the Canadian border. The corn belt of China is also at a risk due to its migratory habit and the cost to Africa, due to this invasion, will exceed $ 6 billion. Maize is a staple food crop in Africa and millions depends on it for food. Hence in Africa and now in Asia it is a global food security issue for millions of people that could be at a risk if FAW is not controlled. The adult moth migrates very fast almost 100 km every night and nearly 500 km, before laying 1,500 eggs on average. The entire life cycle lasts 30 days in tropical climate. There are six larval instars and mostly the destruction is caused by the last three instars and the growing moth pupates in the soil for 10-12 days and the nocturnal adults lay eggs on leaves for about 10 days The pest thrives on about 80 host plants but the most preferable host is Corn/Maize. In Sri Lanka the preferred hosts includes Kurakkan and Sugarcane in addition to Maize. The symptoms of damage- scrapping of leaves, pin holes, small to medium elongated holes. Loss of top portion of leaves fecal pellets in leaf whorl which are easily recognizable. The Comb is also attacked in later stages with a heavy infestation, but after removing the FAW affected portion of the comb the remaining portion is still suitable for consumption and there is no fear of any toxicity. There are two morphologically identical strains––maize strain that feeds on maize and sorghum, and rice strain that feeds on rice and pasture grasses. However, in Sri Lanka only the maize strain has been detected so far. FAW thrives in a climate where drought is followed by heavy rains on a similar way we have experienced last year.

Although new agricultural insect pests are found in Sri Lanka, from time to time a number of factors make FAW unique (FAO Publication 2018)

1

FAW consumes many different crops 2 FAW spreads quickly across large geographical areas 3.FAW can persists throughout the year. Therefore Sri Lanka needs to develop a coordinated evidence based effort to scout FAW for farming communities and effective monitoring by the research staff

 

Management

Since the pest has already arrived in Sri Lanka, the Government/ Ministry of Agriculture should formulate short, mid and long term strategies for its effective management with all stakeholders. Also it has to be clear that a single strategy ex pesticides will not help in effective control but a proper combination of tactics, such as integrated pest management should be employed in the long term. In the short term, the recommended pesticides by the Department of Agriculture should be employed along with cultural and sanitary control strategies. These strategies have now been formulated and what is required to enlighten the farmers and people by utilizing the trained staff. The country should be placed on a war footing and an emergency should be declared in the affected areas to coordinate the control strategies. The integrated control tactics, such as cultural control, should be integrated with pesticides based on the recommendation of the research staff. The residues should be destroyed after harvest and avoid late planting and staggered planting. The Ministry of Agriculture should create awareness among the farmers and train the farmers on early detection of egg masses found on leaves and destroy them by hand. The pesticides for FAW control is recommended by the Department of Agriculture (Please contact Registrar of Pesticides of the Department of Agriculture for the recommended list of Pesticides) and they have to make it available at subsidized rates or given free with technical information considering the emergency. When the larvae are small early detection and proper timing of pesticides are critical for elimination of the pest. With this outbreak some farmers and the private sector is engaged using highly hazardous pesticides which should be avoided to make way for sustainable alternatives. The Department Entomologists should train the farmers for early detection of egg masses when present on 5% of the plants and when 25% of the plants show damage symptoms and live larvae are present on war footing. The economic threshold has been calculated as 2-3 live larvae per plant and the control strategies should commence as soon as this threshold is detected by visual observation. The majority of development officers, agriculture and science graduates working in Divisional Secretariats, are already trained on pest control and their participation on training the farmers for early detection and pesticide selection and application warrants the strategy. Some of the recommended pesticides are follows: Chlorantraniliprole 200g/1SC: Trade name Corogen, Emamectin benzoate 5%SG: Trade name Proclaim,, Flubendiamide 24% WG : Trade name Belt. The Principle Entomologist of the Dry Zone Research Station of the Department of Agriculture ( Mrs KNC Gunawardena) has prepared an effective online presentation on FAW control and this has to be shared by all. The African country Ghana has declared a state of emergency in response to this invasion as Maize is a staple crop which should be followed by us in Sri Lanka.

The long term strategies include early detection. Stopping its spread and initiation of a long term research programme to identify tolerant varieties and granting permission to import such varieties as seeds. The country should ear mark on a Biological control strategy by breeding and releasing FAW parasitoids regularly. In USA larval parasitoids such as Apanteles marginiventris, Chelonus insularis and Microplitis manilae have contributed to keep the pest population down along with egg parasitoids Trichrogramma spp and a similar program should be initiated in the affected districts. Finally the best option is to establish a task force with the involvement of entomologists, extension personnel along with the administrators and scientists working in the universities to ensure the country are safe with regards to food security

 

 

The author has read for a PhD at University of Florida Gainesville in the USA in 1985 and his PhD thesis exclusively deals on Fall armyworm parasitoids and its ecology

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President’s decision on Colombo Port in national interest

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by Jehan Perera

President Gotabaya Rajapaksa has announced that the government will be entering into an agreement with the Adani Group, based in India, to offer them 49 percent of the shares in a joint venture company. This joint venture will include Japanese government financing and will manage one of the terminals in the Colombo port. The entry of Adani Group, into the Colombo port, has been opposed by a wide coalition of organisations, ranging from port workers, and left political parties, to nationalists and civil society groups. These groups have little in common with each other but on this particular issue they have made common cause and even held joint protests together. The main thrust of their objections is that control over the East Terminal of the Colombo port will pass into foreign hands and result in an erosion of Sri Lankan sovereignty.

The cause for alarm, among the protesting groups, may be fueled by the observation that one by one, the ports of Sri Lanka are being utilized by foreign powers. In particular, China has entered into Sri Lanka in a big way, obtaining a 99-year lease in the Hambantota port that it constructed. The Hambantota port, in its early period, showed it was economically unviable in the absence of Chinese cooperation. The burden of debt repayment induced the previous government to enter into this agreement which may become unfavorable in terms of national sovereignty. There were protests at the time of the signing of that lease agreement, too, though not as effective as the present protests regarding the change of management in the Colombo port, which is led by the very forces that helped to bring the present government into power.

In addition to the Hambantota port, control over the South Terminal in the Colombo port, and a section of the harbour, has been given to China through one of its companies on a 35-year lease. In both cases, large Chinese investments have helped to upgrade Sri Lanka’s capacity to attract international shipping lines to make use of the port facilities. The Hambantota port, in particular, could benefit enormously from Chinese ships that traverse the Indian Ocean, the Middle East and Africa. Instead of making refuelling stops elsewhere along the way, such as Singapore, they could now come to Hambantota. However, with these investments would also come a Chinese presence that could cause concerns among international actors that have geopolitics in mind. It may be that these concerns are finding expression in the opposition to the Indian entry into the Colombo port.

 

RATIONAL ANALYSIS

It will not only be Sri Lankans who are concerned about the Chinese presence in the country’s ports. As Sri Lanka’s nearest neighbour, India, too, would have concerns, which are mirrored by other international powers, such as Japan. It might be remembered that when Japan’s prime minister visited Sri Lanka, in 2014, there was a diplomatic furor that a Chinese submarine entered the Colombo port, unannounced, even to the Sri Lankan government, and docked there. With its excellent relations with China, that go back to the 1950s, when the two countries signed a barter agreement, exchanging rice for rubber, most Sri Lankans would tend to see such Chinese actions in a benign light. In recent years, China has emerged as Sri Lanka’s largest donor and its assistance is much appreciated. However, India’s relations with China are more complex.

The two countries have massive trade links, but they have also gone to war with each other due to territorial disputes. Even at the present time Indian and Chinese troops are in a stand-off on their disputed Himalayan border. In this context, India would be concerned that the Chinese presence in Sri Lankan ports could eventually take the form of an overall strategy to encircle it and use this leverage to India’s disadvantage. Sri Lanka’s location at the bottom of the Asian continent gives it a strategic importance in the Indian Ocean that goes beyond any possible India-China rivalry. The recent visit of US Secretary of State to Sri Lanka included an acerbic exchange of words between the US and Chinese representatives on that occasion and an open call to Sri Lanka to take sides, or not to take sides. As a small actor in itself, Sri Lanka would have no interest in getting involved in international geopolitics and has a longstanding policy of non-alignment and friendship with all.

More than anyone else, President Gotabaya Rajapaksa would be aware of these geopolitical issues. As Defence Secretary, during the years of war with the LTTE, he was a key member of the government team that obtained wide ranging international support for prosecuting the war. Today, the President’s key advisers include those with military backgrounds who have special expertise in geopolitical analysis and who have spent time in leading military academies in different parts of the world, including the US, China and India. This contrasts with the more parochial thinking of political, nationalist and even civil society groups who have come out in opposition to the agreement that the government has entered into with the Indian company to manage the Eastern Terminal of the Colombo port.

 

GEOPOLITICAL IMPERATIVE

President Rajapaksa was elected to the presidency in the context of the security debacle of the Easter Sunday suicide bomb attacks and with the expectation that he would provide clear-cut leadership in protecting the country’s national security without permitting partisan interests from becoming obstacles. In his meeting with the representatives of the trade unions, opposing the handing of management of the Eastern Terminal to foreign hands, the President is reported to have said that geopolitics had also to be taken into account. As many as 23 trade unions, representing the Ports Authority, the National Organisations collective, and a number of civil organizations, have joined the formation of a new national movement named the ‘Movement to protect the East Container Terminal’.

One of those political representatives at the meeting, leader of the Frontline Socialist Party (FSP), Pubudu Jayagoda, is reported to have said, “When trade unions met President Gotabaya Rajapaksa on Wednesday (13), he told them about the broad geopolitical factors in play. This is reminiscent when the unions met former Prime Minister Ranil Wickremesinghe a few years back. The unions told Wickremesinghe what they told Rajapaksa––the ECT could be operated by Sri Lanka in a profitable manner. Wickremesinghe told the union representatives, ‘You are talking about the port, I am talking about geopolitics’.” However, former Prime Minister Wickremesinghe may not have had the necessary political power to ensure that his vision prevailed and failed to ensure the implementation of the agreement.

Entering into the agreement with the Indian company will serve Sri Lanka’s national interests in several ways. By ensuring that India is given a presence in Sri Lanka’s most important port, it will reassure our closest neighbour, as well as Japan, which has been Sri Lanka’s most consistent international donor, that our national security interests and theirs are not in opposition to each other. Second, it takes cognizance of the reality that about two-thirds of the Colombo port’s shipping is due to transshipment with India, and thereby ensures that this profitable business continues. Third, it will give Sri Lanka more leverage to negotiate with India regarding key concerns, which includes Indian support to Sri Lanka at international forums and in providing guarantees for the unity of the country in the face of possible future threats and the need to ensure devolution of power to satisfy ethnic minority aspirations.

 

 

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