Thailand says 40 year old smallpox vaccines are effective against monkeypox

Thailand has a stockpile of smallpox vaccines in cold storage which were produced more than 40 years ago in 1979 and 1980. Not only are the vaccines still effective against smallpox, but they are 85% effective against monkeypox too, according to Thailand’s Department of Medical Sciences (DMS).

The vaccines could be used in the instance that the global monkeypox outbreak becomes a public health emergency in Thailand and the government is unable to procure fresh, more recently produced vaccines.

There are 10,000 vials in storage which each contain 50 doses of the vaccine, amounting to around 500,000 doses in total. The vaccines are left over from when smallpox was completely eradicated in Thailand by 1980. The vials are from 13 batches, produced in 1979 and 1980, and have been stored at 2-8 degrees Celsius for over 40 years.

At present, the monkeypox virus is not a ‘public health emergency’ in Thailand but the Ministry of Public Health is monitoring the situation after Thailand’s first ever case of monkeypox was recorded in Phuket last week. Monkeypox was declared a global health emergency by the World Health Organisation (WHO) on Saturday after more than 16,000 cases were recorded worldwide.

Although, since the 27 year old Nigerian man who tested positive for monkeypox fled Phuket and swam to Cambodia via the Sa Kaeo River, Thailand’s official recorded number of monkeypox cases is now technically back down to zero.

In preparation for the arrival of monkeypox in the kingdom, a sample of the frozen vaccine was inspected by the DMS in May. The vaccines passed five quality tests for appearance, physiochemical properties, safety, identity, and potency, according to Director-General of the DMS Dr Supakit Sirilak.

The DMS did not detect any issues or contaminations in the vaccine sample. The 40 year old vaccines conform with the WHO’s international standards and are 85% effective at preventing monkeypox too, according to Dr Supakit.

The old vaccines will only be put to use if the monkeypox outbreak worsens in Thailand. The DMS is currently attempting to cultivate the monkeypox virus in the laboratory to investigate the potential of producing a separate monkeypox vaccine.

SOURCE: Nation