DMS says four decades old smallpox vaccine in storage still effective against monkeypox

The Government Pharmaceutical Organisation (GPO) confirmed today (July 25) that Thailand possesses a stockpile of a smallpox vaccine which is 85% effective at protecting against monkeypox.

It also confirmed that the smallpox vaccines have been kept in storage for more than 40 years, reports NNT.

Although based on old technology, this vaccine provides Thailand with a backup option if newer types cannot be procured, health officials said.

Department of Medical Sciences (DMS) Director-General Supakit Sirilak revealed the vaccine doses were stored in powder form at 2-8°C. The doses were from a total of 13 production batches and were manufactured in 1979 and 1980. There are 10,000 vials in total, each containing 50 doses of the vaccine. The GPO stockpile, therefore, amounts to 500,000 doses.

Dr Supakit said that all of the doses were of the live vaccine type. The DMS has inspected the quality of the vaccine and did not find any issues with acidity or basicity, neither were any contaminations detected, he confirmed.

The vaccine’s efficacy remains at a good level and conforms with World Health Organization (WHO) standards. Dr Supakit said the vaccine is 85% effective at preventing monkeypox.

The DMS is currently cultivating the monkeypox virus in its laboratory. If successful, it will discuss the potential production of a monkeypox vaccine with relevant agencies.

Dr Supakit further explained there are three types of smallpox vaccines currently recommended by the WHO. These include second generation and third generation vaccines produced in the United States and fourth generation vaccines made in Japan.

He added that the third generation vaccines are most likely to be put into use if the monkeypox situation globally necessitates it.