Covid-19 mRNA vaccines such as Moderna and Pfizer are more effective for patients suffering from various types of comorbidities including diabetes, cancer, and kidney disease.
Experts have recommended using an mRNA vaccine as preliminary results from a recent study have found that antibody concentration in the Moderna vaccine was twice as high as that of Covishield, and the antibodies last longer in vaccine recipients with comorbidities.
Messenger RNA, or mRNA, vaccines teach body cells how to make a protein that triggers an immune response.
Dr Ashraful Hoque, an assistant professor with the Blood Transfusion Department of the Sheikh Hasina National Institute of Burn and Plastic Surgery, studied the effects of the Moderna vaccine on 100 comorbid patients who received two doses of the vaccine.
The ELISA (Enzyme-Linked Immunosorbent Assay) method was followed in the study, which showed high antibody concentrations – between 14 and 18 in patients' bodies two weeks after receiving two doses of the vaccine.
Among the participants in the study, 72 were men and 28 were women – all over 50 years in age.
Previously, Dr Ashraful also studied 1,000 people who received two doses of the Oxford-AstraZeneca Covishield vaccine. After receiving two doses of the vaccine, 100% antibodies were produced in their bodies.
Among the participants in that study, 350 were with comorbid conditions and the antibody concentration in their body ranged from six to eight.
"Comorbid patients vaccinated with Covishield produced fewer antibodies than others because their cells were weaker, but we got more antibodies in those who were vaccinated with Moderna.
"The antibodies from Covishield will not last long too," Dr Hoque told The Business Standard.
Moderna vaccination started on 13 July and 55 lakh doses of the vaccine have arrived in the country to date. Nearly 26 lakh people have received their first dose and almost 24 lakh people have taken the second dose.
At present, the Department of Health has 10 lakh doses of Pfizer vaccine in stock. Another 50 lakh doses are expected to arrive in the country soon.
Dr Ashraful Hoque said the mRNA vaccines are coming only as gifts and from Covax. Good results can be obtained if those vaccines are given to comorbid patients instead of the general population.
Citing another study, he added that Sinopharm, which is an inactivated vaccine, provides long-term protection. Therefore, this vaccine should be given to healthy people and young patients.
An inactivated vaccine (or killed vaccine) is a vaccine consisting of virus particles, bacteria, or other pathogens that have been grown in culture and then killed to destroy the pathogen's disease-producing capacity.
Professor Dr Sayedur Rahman, chairman of the Department of Pharmacology at Bangabandhu Sheikh Mujib Medical University, told The Business Standard, "It is a good finding that the mRNA vaccine works well in comorbid patients. However, it is not yet time to come to a conclusion about it."
He said, "There is a shortage of mRNA vaccines in our country. So, people over the age of 55 should be vaccinated – with whichever vaccine is available – on a priority basis, as the death rate is higher among them."
Covid-19 vaccination started across the country on 7 February with the Covishield vaccine. Due to a vaccine crisis, the vaccination programme slowed down a bit for some time, but later Pfizer, Moderna and Sinopharm vaccines were introduced.
So far, more than 2.24 crore people have received at least one dose of vaccine in the country, and more than 1.48 crore people have received two doses of vaccine.