Immunologist on what to ‘mix and match’
With mixing and matching seeming to be an option for nearly 600,000 people who have got the first dose of AstraZeneca, the Sunday Times asked Consultant Immunologist Dr. Rajiva de Silva of the Medical Research Institute for his views.
Quoting a placebo- controlled study done in the United Kingdom, Dr. de Silva said that a mix of AstraZeneca and Pfizer vaccines had found a mild increase in the side- effects such as fever and malaise after the second dose.
“There was nothing serious. Those who had got this ‘mixed’ jab just stayed home from work for a day,” he said, while a small observational study in Spain on the effectiveness of a mix of AstraZeneca and Pfizer, as the first and second doses respectively, had shown it to be “immunogenic”.
Commenting as an immunologist, Dr. de Silva said that mixing mRNA (Pfizer) and adenovirus (AstraZeneca) vaccines would “broaden” the immune response.
The AstraZeneca vaccine’s good T- cell response would be complemented by the Pfizer vaccine’s good antibody response, he said, reiterating that if these two vaccines are mixed and matched it would broaden the immune response.
Vaccines received by Sri Lanka: January 28 – 500,000 doses of AstraZeneca COVISHIELD (donation from India) February 25 – 500,000 doses of AstraZeneca COVISHIELD (bought from India) March 7 – 264,000 doses of AstraZeneca COVISHIELD (from COVAX, the global vaccine initiative) March 20 – 600,000 doses of Sinopharm (donation from China) May 4 – 15,000 doses of Sputnik V (bought from Russia) May 26 – 500,000 doses of Sinopharm (donation from China) May 27 – 50,000 doses of Sputnik V (bought from Russia) June 9 – 1 million doses of Sinopharm (bought from China) June 11 – 65,000 doses of Sputnik V (bought from Russia). These were second doses of Ad 5 July 2 – 1 million Sinopharm (bought from China)
Vaccines likely to arrive in Sri Lanka shortly: Around 3 million doses of Sinopharm in July and another 4m in August Around 1m doses of Moderna through COVAX within a week (with a possibility of 2m more from benevolent countries) 264,000 doses of AstraZeneca through COVAX Three tranches of 27,000 doses each on a weekly basis from Pfizer in July A promise of 1.5 mil
lion Sputnik V doses