It has been almost two years since World Health Organisation declared the covid-19 a pandemic on 11 March 2020. All over the world including the Indian people are taking booster vaccines but according to infectious disease specialist, Dr. Gili Regev-Yochay of Sheba Medical Centre in Tel HaShomer, Israel, not even the fifth dose after the fourth dose will stop the coronavirus in long term.
People Need A Fourth Dose Of The Covid-19 Vaccine
A published study in Israel suggests that the fourth dose of the same vaccine i.e Pfizer-BioNTech or Moderna adds on very small protection compared to provided by the previous three shots. After taking the third booster dose, antibodies increase quickly, but after one month, antibodies start to decline, and three months later, they decrease to about 50%. Regev-Yochay concluded that the booster dose doesn’t boost immunity it only restores the lost protection.
Morbidity and Mortality Weekly Report published a study that the three doses of vaccine provide protection about 90% against hospitalization with an omicron virus up to two months reckoned last dose and this protection declines to 80% after four months of the last dose.
This small protection for healthy people under 65 years of age will not provide a significant change but this booster dose will extend protection for people over the age of 65 years who have a higher risk of hospitalization as they are more prone to comorbidities.
Omicron has changed the concept of booster doses because boosters were used to increase the neutralizing antibodies, but after omicron boosters fail to prevent infections for a long time. Authorities need real-world data on vaccine and booster doses to make decisions.
In Israel data collected from June to November 2021 when the Delta variant was dominant showed that immunity gained from third (mRNA booster) declined in one month only same as declined after taking two doses. In the United Kingdom data collected during the omicron variant also suggests immunity from booster dose in omicron case decrease with faster rate as compared to the rate in the delta version.
An immunologist at Yale University, Akiko Iwasaki says that scientists have no information about the need for extra shots for people after fourth dose because it totally depends on the rate of immunity decline. The food and Drug Administration is also waiting before they recommend boost vaccine to anyone as they have no data to calculate.
The director of the FDA’s Centre for Biologics Evaluation Dr. Peter Marks says that more data on the effectiveness and safety of COVID-19 vaccine and booster dose will help determine the need for additional booster doses.
United States Centre for Disease Control and Prevention also has to refer data for recommended booster dose, but it recommends the fourth dose to people who are immunocompromised. Study on efficacy and safety of omicron coronavirus vaccine also going by Pfizer and other vaccine-specific companies.
Firstly, Israel in December announced to roll out above age 60 years, medical workers, and people with a weak immune system for the fourth dose if they have completed four months after their third dose. The Public Health Agency of Sweden recommended booster dose for everyone above 80 years in country. UK’s Department of Health and Social Care also announced booster dose for adults above 75 years and many other countries may announce same after some time.
According to Marm Kilpatrick, University of California Santa Cruz, a better solution for these endless boosters can be developing a new vaccine that would have a long and enduring effect and allow protection against present and emerging strains.
A vaccine that will cover all strains and other related viruses is difficult because there is substantial uncertainty in dealing with the evolution of the virus. Infectious disease specialist Peter Mclntyre at University of Otago, New Zealand priorities should be given individuals with weak immune systems by giving booster doses to keep them out of hospitals until we have a new developed vaccine.