Antibodies drop 50 per cent in 3 months of Pfizer, AstraZeneca jabs: Study

Total antibody levels produced by both Pfizer and AstraZeneca appear to start declining from as early as six weeks after two vaccine doses and can reduce by more than 50 per cent over 10 weeks according to a new study stressing the need for booster dosesThe study led by researchers of the University College London showed that the waning effect of the vaccine doses were consistent across all groups of people regardless of age chronic illnesses or sexPublished as a research letter in The Lancet the study included data from over 600 people and showed antibody levels are substantially higher following two doses of the Pfizer vaccine than after two doses of the AstraZeneca jabThey are also much higher in those with prior SARSCoV2 infectionThe researchers highlighted 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 diseaseFor Pfizer antibody levels reduced from a median of 7506 UmL at 2141 days to 3320 UmL at 70 or more days For AstraZeneca antibody levels reduced from a median of 1201 UmL at 020 days to 190 UmL 67644 at 70 or more daysAlso read Brazil scraps Covaxins EUA application after Bharat Biotech terminates pact with partnersThe levels of antibody following both doses of either the AstraZeneca or Pfizer vaccine were initially very high which is likely to be an important part of why they are so protective against severe Covid19 said Maddie Shrotri from the UCL Institute of Health InformaticsHowever we found these levels dropped substantially over the course of two to three months If they carry on dropping at this rate we are concerned that the protective effects of the vaccines may also begin to wear off particularly against new variants but we cannot yet predict how soon that might happen she addedThe findings support recommendations from the UK Joint Committee on Vaccination and Immunization JCVI that adults who are clinically vulnerable those aged 70 years or over and all residents of care homes for older adults should be prioritised for booster dosesIn addition those who were vaccinated with the AstraZeneca vaccine including most care home residents are likely to have much lower antibody levels than those vaccinated with the Pfizer vaccine so this may also need to be considered when deciding who should be prioritised when boosters are rolled out said Professor Rob Aldridge from the UCL Institute of Health InformaticsHowever the study included only a small sample size and different people will have different levels of immunity depending on the virus neutralizing ability of their antibodies as well as their Tcell responsesThus additional research is important to establish if there is an antibody level threshold needed for protection against severe disease the researchers notedThis story has been sourced from a third party syndicated feed agencies Midday accepts no responsibility or liability for its dependability trustworthiness reliability and data of the text Midday managementmiddaycom reserves the sole right to alter delete or remove without notice the content in its absolute discretion for any reason whatsoever