Even as India reported fewer than 30,000 daily Covid-19 cases for the first time in 132 days, a new study published in The Lancet has rekindled apprehensions over the efficacy of Covid vaccines. According to the study, the total antibody levels start to wane six weeks after complete immunisation with Pfizer and AstraZeneca vaccines, and can reduce by more than 50% over 10 weeks.
The researchers from the University College London (UCL) in the UK noted that if the antibody levels carry on dropping at this rate, there are concerns that the protective effects of the vaccines may also begin to wear off, particularly against new variants. However, they said, how soon that might happen cannot be predicted yet.
Antibody levels are substantially higher following two doses of the Pfizer vaccine than after two shots of the AstraZeneca preventive, known as Covishield in India, the UCL Virus Watch study added. Interestingly, antibody levels were also much higher in vaccinated people than those with prior SARS-CoV-2 infection. The findings based on data from over 600 people aged 18 and above were consistent across all groups of people regardless of age, chronic illnesses or sex, according to the researchers.
The authors highlight that although the clinical implications of waning antibody levels are not yet clear, some decline was expected and current research shows that vaccines remain effective against severe health complications. The researchers underlined that different people will have different levels of immunity depending on the virus neutralising ability of their antibodies as well as their T-cell responses.
Meanwhile, for the first time in 132 days, India reported fewer than 30,000 daily cases. As per the data shared by the Union Health Ministry, 29,689 new cases were reported in the last 24 hours while the death toll climbed to 4,21,382 with 415 daily fatalities. The latest dip in new cases took India›s active caseload less than 4,00,000 after 124 days, which now is at 3,98,100.
Active cases constitute 1.27% of total cases. The Weekly Positivity Rate remains below 5%, currently at 2.33%, while the daily positivity rate at 1.73%, remains below 5%, the data further read. As per the data, India’s Cumulative Covid Vaccination Coverage surpassed 44.58 crore (44,58,39,699), as per the 7 pm provisional report on Tuesday. More than 36.87 lakh (36,87,239) vaccine doses were administered yesterday.