Scientists uncover factors influencing waning immunity with Pfizer COVID-19 vaccine
pharmafile | November 22, 2021 | News story | Sales and Marketing |
Scientists have discovered multiple factors influencing declining immunity over time with the Pfizer COVID-19 vaccine, according to News Medical.
In recent months, an increasing volume of data has revealed that immunity against COVID-19 wanes six months after vaccination. Immunological studies have reported a steady decline of antibody levels among vaccinated individuals, and long-term follow-up of vaccine trial participants has revealed a growing risk of breakthrough infection. Most of these studies do not even account for the threat of the Delta variant, vaccines are not that effective at recognising and protecting against new variants.
The Japanese study is called, “Attenuation of antibody titers during three to six months after the second dose of the BNT162b2 vaccine depends on sex, with age and smoking as risk factors for lower antibody titers at six months”. It revealed that old age and smoking are among the risk factors associated with greater waning immunity following vaccination, and these had the lowest antibody titers.
The study involved 365 vaccinated healthcare workers from a hospital in the Tochigi prefecture, including 250 women and 115 men. The median age was 44 years, and nurses and doctors made up 56.2% of the study population.
It was found that women were more likely than men to experience a rapid decline in antibody levels three to six months after receiving their Pfizer dose, and experienced a 6.5% faster rate of decline. The median rate of change in antibody titers was 31.6% in women, whilst men showed a -25.1% rate of change.
The US has recently authorised booster jabs for adults over the age of 18, and people over the age of 40 in the UK are now permitted to receive theirs. It is anticipated that these booster shots will make a difference in lowering the rate of COVID-19 infection in the long-term.