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?
On October 6, Sweden and Denmark, followed by Finland a day later, suspended the use of Moderna’s mRNA vaccine for younger age groups after reports pointed to an increase in the number of myocarditis and pericarditis cases. Why three Nordic countries have suspended Moderna vaccine. On October 6, Sweden and Denmark suspended the use of … Continue reading Why three Nordic countries have suspended Moderna vaccine
Young children rarely suffer from severe disease, yet mRNA vaccines might soon be greenlighted by the FDA after Pfizer submitted Phase-2/3 data for initial review. The company expects to submit data of children 2-4 years and 6 months to 1 year by the end of the year. Vaccinating young children while even health-care workers in … Continue reading Soon mRNA vaccines for young children who rarely suffer from severe disease
Moderna, which was funded $1 billion for research by the U.S. government, said in October 2020 that it will not enforce COVID-19-related patents against those making vaccines intended to combat the pandemic. But the company has refused to transfer technology to the South African hub to manufacture its mRNA vaccines for distribution to the African … Continue reading mRNA vaccine manufacturers loathe to share know-how
A large real-world study found natural immunity offers superior and long-lasting protection than vaccination. But vaccination was still equally effective in preventing deaths. The study does not tell if the level and duration of protection varies depending on the severity of the disease, and whether asymptomatic infection confers the same protection as those with the … Continue reading Natural immunity is superior to protection conferred by vaccination but not a safe, preferable option
The emergence of highly contagious new variants, breakthrough infections even among the fully vaccinated and such people spreading the virus to others, and reinfections in the unvaccinated have made the race to reach the magical herd immunity threshold to successfully break the transmission chain and return to normal times looks like chasing a mirage. In … Continue reading Is the race to reach herd immunity like chasing a mirage?
On April 13, India permitted fast-track approval of COVID-19 vaccines developed, tested and approved outside the country. The decision has been taken to “expand the basket of vaccines for domestic use and hasten the pace and coverage” of COVID-19 vaccination. But before mass roll out of the vaccines that are developed and tested abroad can … Continue reading In a major shift, India fast-tracks restricted use approval for vaccines developed in other countries
While it is unclear if pre-existing antibodies to adenovirus vector will affect vaccine efficacy, it is possible that repeated vaccination using adenovirus-based vaccine either as a booster or as annual vaccination, if the need arises, will result in reduced efficacy due to vector immunity.
Influenza vaccines are decided based on strains recommended by WHO twice a year for northern and southern hemisphere vaccines. They require animal studies in ferrets and small safety and immunogenicity studies, based on measurement of antibodies. If we had a reasonable antibody measurement which could reflect protection, then we could potentially follow a similar strategy … Continue reading Proving variant-specific efficacy will be a logistic nightmare, very expensive: Gagandeep Kang