Booster doses only mitigate disease severity, do not fully prevent infection

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

Are there clinical trial data to support a homologous vaccine booster?

While data from a homologous booster clinical trial has now become available for Covaxin, there is no supporting data from India for Covishield. Yet, Covishield makes for up to 90% of vaccines administered to adults so far in India. On January 5, five days before the roll-out of the ‘protection dose’, scientifically called a third … Continue reading Are there clinical trial data to support a homologous vaccine booster?

India widens the vaccine safety net by immunising teenagers above 15 years

Covaxin was found to be safe and immunogenic in teenagers during a phase-2/3 clinical trial; only 175 adolescents aged 12 to 18 years were studied. The data of the trial, which is yet to be peer-reviewed, were posted on a preprint server on December 29. Nearly a year after the rollout of COVID-19 vaccines for … Continue reading India widens the vaccine safety net by immunising teenagers above 15 years

The basis on which India approves precaution dose remains unclear

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 should prepare for the worst with Omicron

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

How the idea of vaccine protection changed in one year

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

Does the Omicron variant make a case for booster doses?

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?

Groping in the dark on booster doses

Though over 1.26 billion doses have been administered as on December 4 with nearly 85% receiving one dose but only over 50% being fully vaccinated. Over 8% of health-care workers, 30% of those above 60 years and over 33% of people aged 45-59 years are yet to be fully vaccinated. And there is no scientific … Continue reading Groping in the dark on booster doses

Mechanism of blood clots after Oxford vaccine administration found

A study published has revealed for the first time the mechanism responsible for blood clot arising from thrombosis with thrombocytopenia syndrome (TTS) following vaccination with AstraZeneca vaccine. A multi-institutional study published on December 1 in the journal Science Advances has revealed for the first time the mechanism responsible for blood clot arising from thrombosis with … Continue reading Mechanism of blood clots after Oxford vaccine administration found

India falters in administering the second dose

Even as the daily fresh cases have been on an overall downward trend since it peaked in early May, the pace of vaccination has slowed down sharply since hitting a peak in September. Only 38% have been fully vaccinated though nearly 80% of all eligible adults have received the first dose. Nearly 43% of people … Continue reading India falters in administering the second dose