A local study has confirmed that 93.4 percent of the individuals developed antibodies against the novel coronavirus after receiving the first dose of the AstraZeneca Covishield vaccine.
Director of the Allergy, Immunity and Cell Biology Unit at the Sri Jayewardenepura University Dr. Chandima Jeewandara said the research was conducted based on samples obtained from 655 healthcare workers who received the first jab of the AstraZeneca Covishield vaccine.
Dr. Chandima Jeewandara said they assessed the immunogenicity of the individuals after one month of receiving the dose. Accordingly, they have observed 93.4 percent had favourable antibodies while 97.1 percent of the individuals developed neutralising antibodies which prevent severe cases of COVID-19.
Nearly 500,000 persons did not receive the second jab of the Covishield due to supply issues.
Dr. Chandima Jeewandara said samples of 553 persons were tested for antibody responses during the period between four and 16 weeks of receiving the vaccine dose.
He said although 93.4 percent of persons developed antibodies, the percentage of neutralising antibodies after 28 days had decreased to 26.1 percent.
Dr. Chandima Jeewandara said the findings are alarming since the neutralising antibodies are imperative to fight against emerging variants such as Delta and Alpha strains.
He said therefore they have determined that neutralising antibodies had reduced significantly during the period between four to 16 weeks.
Dr. Chandima Jeewandara said they have to conduct further studies to determine whether different dosing schedules will help the development of antibody responses.
He added that a booster shot will likely to provide additional protection and prevent people from having a severe bout of COVID-19.