None of the COVID-19 vaccines currently being used for immunisation offer sterilising immunity, which completely prevents infection. Administering a booster dose will surely increase the level of neutralising antibodies but even that does not guarantee full protection from infection. Nearly a year after India rolled out the COVID-19 vaccination programme, administering a ‘precaution dose’, scientifically … Continue reading Booster doses only mitigate disease severity, do not fully prevent infection
The unprecedented speed at which the Omicron variant is spreading in countries that have high levels of testing, the number of people a single infected person can spread the virus to, and doubling time of less than three days are a loud warning that things can go out of control in a short while. India … Continue reading Even if mild, Omicron variant can overwhelming health-care settings
On November 22, 2021, Dr. Balram Bhargava said there is no scientific evidence so far to support the need for a booster vaccine dose against COVID-19. The priority was on administering the second dose to all adults. No new evidence from India has become available to support an additional dose after Dr. Bhargava's assertion. There … Continue reading The basis on which India approves precaution dose remains unclear
India has been witnessing a surge in cases in many States. There is no reason to believe that the variant will behave differently in India or that Indians have some unknown shield of protection against the virus. The Omicron variant is galloping across the U.S. and many countries in Europe at a pace never seen … Continue reading India should prepare for the worst with Omicron
Positive samples sent for genome sequencing to confirm for the Omicron variant are almost primarily restricted to international passengers. Not only are the testing rates across India low, most of the RT-PCR test kits used in most States do not have the S-gene target in the primer, which can detect the BA.1 sub-lineage. Also, the … Continue reading Is the current testing, sequencing strategy missing Omicron cases in India?
As the virus evolved, our perception of protection conferred by vaccines changed dramatically. From the popular notions of herd immunity and vaccinating our way out of the pandemic, the discussion is now centred around booster doses and the eventuality of living with the virus. As the virus evolved, our perception of protection conferred by vaccines … Continue reading How the idea of vaccine protection changed in one year
What is the major objective of a booster dose -- to protect from infection or protect from severe disease and death, who should get it first whenever it is approved, is there enough evidence recommending for their use, and should we give boosters when primary immunisation is not complete? Dr. Chandrakant Lahariya, physician epidemiologist and … Continue reading Does the Omicron variant make a case for booster doses?
The study conducted on 39 individuals who received two doses of Covaxin found that the vaccine induces memory T cells in about 85% of the subjects. The T cell responses are largely preserved against the variants, including the Delta variant. A small study conducted on 71 individuals who received two doses of Covaxin found that … Continue reading Covaxin elicits immune memory to virus up to six months, study finds
While most of the new daily cases reported are among the unvaccinated, breakthrough infections and hospitalisations are being reported in the fully vaccinated too. However, the deaths have predominantly been among the unvaccinated. With the staggering increase in the number of daily fresh coronavirus cases and deaths in many countries in Europe, the continent has … Continue reading Virus rages in Europe as epicentre shifts
The global death toll from COVID-19 crossed five million on November 1 and yet the the global number of reported cases and deaths from COVID-19 is now increasing for the first time in two months. The first million deaths were recorded on September 8, 2020, nearly nine months after the first death occurred, while the two-million mark was breached three and a … Continue reading ‘Pandemic far from over’ even as global death toll crosses five million