Pfizer and Moderna's COVID-19 vaccines don’t lower sperm count, says study; all you need to know

The Pfizer and Moderna vaccines against CVOID-19 do not harm male fertility, suggests a new study published in the  journal JAMA. The study, which involved 45 healthy male volunteers aged 18 to 50 years, found that the levels of sperm in participants remained at healthy levels after they got two doses of the mRNA COVID-19 vaccine by Pfizer-BioNTech and Moderna, reports said. Why is it relevant? The potential negative impact of COVID-19 vaccines on male fertility has been one of the many reasons for vaccine hesitancy across the world. This study by the University of Miami in the US brings much-needed clarity into the topic and is likely to help persuade more male members of society in getting vaccinated. “One of the reasons for vaccine hesitancy is the potential negative effect on fertility,” the authors of the study from the University of Miami in the US noted. “Because reproductive toxicity was not evaluated in the clinical trials and SARS-CoV-2 has been associated with decreases in sperm parameters, we assessed sperm parameters before and after mRNA vaccine administration, they said. Does COVID-19 impact male fertility? In a report published in the journal Reproduction in January this year, researchers had said that COVID-19 can cause increased sperm cell death , inflammation and so-called oxidative stress. “These findings provide the first direct experimental evidence that the male reproductive system could be targeted and damaged by COVID-19,” the authors concluded. Experts commenting on the research, however, said the capacity of the virus to compromise fertility in men remains unproven. Prior to this, in 2020, a new study in China had indicated that SARS-CoV-2 may affect the process of spermatogenesis (sperm formation) and lead to low sperm count. The findings of the study were published in the open-access journal EClinical Medicine and also published by The Lancet journal. However, the potential impact of COVID-19 vaccines on male fertility was not part of these studies. How was University of Miami study conducted? The participants were pre-screened to ensure they had no underlying fertility issues. Those with COVID-19 symptoms or a positive test result within 90 days were excluded. The men provided a semen sample after two to seven days of abstinence, prior to receiving the first vaccine dose and approximately 70 days after the second shot. Semen analyses were performed by trained andrologists as per World Health Organisation guidelines and included semen volume, sperm concentration, sperm motility, and total motile sperm count (TMSC). What did the University of Miami study find? In the study of sperm parameters before and after two doses of a COVID-19 mRNA vaccine, there were no significant decreases in any sperm parameter among this small cohort of healthy men, the researchers found. Sperm concentration and total motile sperm count at the beginning of the study were 26 million/milliliter (mL) and 36 million, respectively. After the second vaccine dose, the median sperm concentration significantly increased to 30 million/mL and the median TMSC to 44 million. Semen volume and sperm motility also significantly increased, the researchers said. Because the vaccines contain mRNA and not the live virus, it is unlikely that the vaccine would affect sperm parameters, they said. The limitations of the study include the small number of men enrolled, short follow-up, and the lack of a control group. The researchers also noted that while semen analysis is the foundation of male fertility evaluation, it is an imperfect predictor of fertility potential. With inputs from PTI