In Pakistan, anti-snake venom (ASV) is often described as a ‘vaccine’ even though it is actually a serum. This mix-up appears frequently in public reporting. Recent news reports about the proceedings of Sindh Assembly’s Public Accounts Committee have used the terms ‘anti-snakebite vaccine’, ‘anti-snake venom vaccine’ and ‘ASV vaccine’. Technical sources, however, are accurate. The National Institute of Health, for instance, lists ‘anti-snake venom serum’ and ‘anti-rabies serum’ separately from preventive vaccines, and provincial documents clearly use the term ‘antivenom’. The key difference here is simple. While a vaccine protects before exposure, a serum is a treatment post-exposure.

According to the World Health Organi- sation, vaccines train the immune system in advance, as was seen during the Covid epidemic a few years ago.

On its part, a serum works very differently. ASV is a serum used after a bite and only in an emergency. The WHO explains that antivenom is made by immunising donor animals with venom, and then extracting antibodies that neutralise it inside the human body. The same mechanism applies to anti-rabies serum or rabies immuno-globulin. Simply put, serums give short- term protection after exposure, while vaccines build long-term immunity.

Understanding the difference between serum and vaccine is important because Pakistan already struggles with low health literacy. Many people do not have access to clear and simple medical information in the country. Terms like vaccine, serum, immunoglobulin or antivenom can be confusing for them. This confusion has the potential to affect behaviour, resulting in treatment delays and loss of trust in the healthcare system. Using correct terms is not a technical concern; it is a critical element in terms of public safety. Better wording supports public safety. Small improvements in how we communicate health terms can help people make safer decisions, and strengthen their trust in the national healthcare system.

Talib Haider

Karachi