Important points from the lecture by Dr Nitin Shah on 13th Jan 2022 on covid-19 latest vaccinations
- As far as the booster dose is concerned giving killed vaccine after two primary doses of killed vaccine gives 3.5 times rise in neutralizing antibodies, whereas giving COVAVAX/Nova wax as a booster will give 8 times rise in neutralizing antibodies, whereas giving any mRNA vaccines like Pfizer or moderna will give 24 times rise in antibodies.
As of now, January 2022, in India we don’t have a choice so it would be worthwhile to go ahead and take the same ancestral dose as booster, that means people who have taken Covaxin to take Covaxin and people who have taken a COVISHIELD should take COVISHIELD.
- Booster is recommended nine months after the the second dose, However there are countries like Israel which has given the earliest booster dose at four weeks after the second dose.
- Covishield / Covaxin can be given along with any vaccine as they are killed vaccines.
- Omicron variant escapes the neutralizing antibodies as well as monoclonal antibodies, However vaccination gives protection against severe disease.
- The present Omicron variant causes less serous disease as compared to previous variant, still it is worthwhile taking the booster because we don’t know when a new variant mutation can crop up
- Infected – Symptomatic people can take the vaccine 3 months after the infection.
But Infected – Asymptomatic people can take the vaccine 1 month after the infection
- Pregnant ladies can take the vaccination at the earliest in any trimester of pregnancy , because pregnancy is a higher risk condition for Covid.
- Antibody titres are 4 times higher if we use heterologous vaccine for booster.. however the practical problem in our country is that 90% of the population has received COVISHIELD and only 10% have received COVAXIN
. We may not be able to give 90% doses of COVAXIN as booster because of production constraints Plus COVAXIN has to be reserved for paediatric population as COVISHIELD is not to be given below the age of 18 years
9 Social distancing , masks and sanitization to be continued. DR SUREKHA TAYADE*