COVID-19 jabs can take weeks to work, continued vigilance vital says experts

ECONOMYNEXT – Vaccination against COVID-19 will help bring the death rate down and minimize severe disease but the jab can take weeks to be fully effective and vaccinated people can still spread the virus as asymptomatic carriers, a leading Sri Lankan microbiologist said.

Neelika Malavige, Professor in Microbiology at the Department of Immunology and Molecular Medicine, Faculty of Medicine, University of Sri Jayewardenepura, in a Government Information Department interview urged vaccinated Sri Lankans to stick to health protocols such as masking and regular hand washing.

“No one gets immediate protection right after the jab. It takes about 21 days for the body to produce antibodies after the first dose of AstraZeneca (Covishield). One dose does not provide sufficient protection, which is why we give two,” Malavige said.

Sinopharm also provides considerable protection but only two weeks after the second jab, the professor said. Sri Lanka has decided to give the two doses of the Chinese vaccine four weeks apart.

“In the meantime, you can still get infected and infect others,” she warned.

Taking a new wave of COVID-19 in Singapore as an example, Malavige said vaccinated airport employees were found to have spread the highly transmissible Indian strain of the virus in the city state.

“Everyone at the airport had received the Pfizer jab, so even when they tested positive for COVID-19, they didn’t report severe symptoms. But they still got infected and, as asymptomatic patients, carried the virus into the wider Singaporean society,” she said.

Echoing Malavige, Director of the Infectious Diseases Hospital Dr Ananda Wijewickrama said the primary objective of vaccination is to prevent critical conditions and death.

“People who get the jab can still get infected, but they have a lower chance of developing critical symptoms. It is important to follow health guidelines because we can be vaccinated and still spread it,” he said.

A mutated variant that has only been detected in Sri Lanka suspected to have been mutated from the original COVID-19 virus. The virus has been mainly detected in the Batticaloa district and in the Western Province and was the dominant variant before identifying the UK variant.

According to health authorities, this virus has a lower transmissibility and mortality rate making most of the patients asymptomatic.

Director of Allergy Immunology and Cell Biology Unit of the University of Sri Jayawardenepura Dr Chandima Jeewandara told the privately owned ABC media network that all three vaccines have been proven to be effective against the variants present in the country.

“International research has indicated that the efficacy rate can be changed with these mutations. However, any vaccine that shows an efficacy rate more than 50 percent is considered to be a successful vaccine and all three vaccines are proved to have a higher efficacy rate at the moment,” Jeewandara said.

Jeewandara predicted that Sri Lanka’s ongoing wave of COVID-19, with over 2,500 cases reported a day, will likely be contained by August this year.

“The virus has not changed the way it’s infecting people,” he said.

Vaccination and strict adherence to health protocols will contribute chiefly to containing the spread.

“We should provide at least one type of vaccine to the community.  If the vaccine is being given in your area get it immediately, Wear the mask, keep social distance and avoid any gatherings,” he said.

“The next moth is crucial to Sri Lanka. We expect this wave to be controlled by August,” he added.

Jeewandara said there is no guarantee the virus will disappear. Vaccination is the one strategy to take control of the situation, he added.