• Profile

Heterologous versus homologous COVID-19 booster vaccination in previous recipients of two doses of CoronaVac COVID-19 vaccine in Brazil (RHH-001): A phase 4, non-inferiority, single blind, randomized study

The Lancet Feb 08, 2022

The two-dose vaccine schedule widely involves the use of the inactivated whole-virion SARS-CoV-2 vaccine (CoronaVac, Sinovac). Researchers herein examined if immune responses could be boosted by administering a third dose of the homologous or a different vaccine.

  • In RHH-001, a phase 4, participant masked, two center, safety and immunogenicity study, Brazilian adults (18 years and older) in São Paulo or Salvador, who had received two doses of CoronaVac 6 months previously, were offered a third heterologous dose of either a recombinant adenoviral vectored vaccine (Ad26.COV2-S, Janssen), an mRNA vaccine (BNT162b2, Pfizer–BioNTech), or a recombinant adenoviral-vectored ChAdOx1 nCoV-19 vaccine (AZD1222, AstraZeneca), compared with a third homologous dose of CoronaVac.

  • Researchers randomly assigned a total of 1,240 participants to one of the four groups, of whom 1,239 were vaccinated and 1,205 were eligible for inclusion in the primary analysis.

  • At 6 months after previous immunization with two doses of CoronaVac, there were low antibody concentrations.

  • However, a significant increase occurred in binding and neutralizing antibodies in correlation with all four vaccines administered as a third dose, which could result in improved protection against infection.

  • More robust immune responses were induced and there might be enhanced protection in correlation with heterologous boosting vs homologous boosting.

Go to Original
Only Doctors with an M3 India account can read this article. Sign up for free or login with your existing account.
4 reasons why Doctors love M3 India
  • Exclusive Write-ups & Webinars by KOLs

  • Nonloggedininfinity icon
    Daily Quiz by specialty
  • Nonloggedinlock icon
    Paid Market Research Surveys
  • Case discussions, News & Journals' summaries
Sign-up / Log In
M3 app logo
Choose easy access to M3 India from your mobile!

M3 instruc arrow
Add M3 India to your Home screen
Tap  Chrome menu  and select "Add to Home screen" to pin the M3 India App to your Home screen