Pfizer vaccine prevents severe Covid-19 for six months: study

A US study has found that two doses of Pfizer Covid-19 vaccine prevent severe infection for upto six months.

After an average period of three to four months, fully vaccinated people were found to be 73 percent protected against infection and 90 percent protected against hospitalisation, the study published in Lancet has said.

However, protection against Delta variant of Covid fell by nearly 40% over a period of five months. Effectiveness against infections fell from 88% within a month of both the doses to 47% after six months, as per the study. Protection against hospitalization remained high at 90% across all variants, including the deadly Delta.

The research is consistent with preliminary studies by US and Israeli health authorities suggesting that efficacy of vaccinations begins to fade after six months.

The study says that in the future, 'booster shots will be needed to restore the efficacy of vaccines'.

The WHO says that while current vaccines are enough protection against the infection, a third booster shot is not necessary. The health authority also said that it is important to address the inequitable distribution of vaccines before booster shots are administered.