masked doctor extracting vaccine dose from vialShare on Pinterest
Existing vaccinia virus vaccines will be effective against monkeypox, too, study projects. Image credit: Paul Bersebach/MediaNews Group/Orange County Register via Getty Images.
  • Monkeypox is an illness that causes a range of symptoms, including rash, fever, chills, and respiratory symptoms.
  • In 2022, there have been monkeypox outbreaks in several countries, causing growing concern about prevention and treatment.
  • Data from a recent study suggest that currently available vaccines are likely to be effective against the latest variants of the monkeypox virus. Vaccine use may help to reduce the number of monkeypox cases.

The recent monkeypox outbreaks are a growing worldwide health concern. The illness can cause symptoms ranging from mild to severe. Some groups, such as children or people who are immunocompromised, are more at risk for complications.

A new study published in Viruses found that vaccines based on the vaccinia virus (VACV) will likely produce an effective response against the current monkeypox virus.

Two of these vaccines that are available are the MVA-BN and ACAM2000 vaccines.

Before 2022, monkeypox was very rare outside Africa, but there have been recent outbreaks of the illness worldwide. The World Health Organization (WHO) declared monkeypox a public health emergency of international concern in July 2022.

As the Centers for Disease Control and Prevention (CDC) note, monkeypox is caused by the monkeypox virus. This virus is similar to the virus that causes smallpox.

Monkeypox spreads through close or intimate contact with someone who has monkeypox. It can also spread through contact with surfaces used by someone with monkeypox.

People with monkeypox can experience several symptoms. For example, they may have a rash in the genital areas or other body parts, as recent research has found.

They can also experience flu-like symptoms such as muscle aches, fever, chills, and congestion. Most people are not at risk for severe illness from the monkeypox virus.

It typically takes a few weeks to recover fully. However, some people, such as those who are immunocompromised, may become more seriously ill.

Currently, there are a few vaccines that can be utilized to help protect those who are most at risk for developing monkeypox. However, the full effectiveness of these vaccines is unknown.

Researchers in the current study examined the potential effectiveness of a few vaccines that can be utilized against monkeypox. Specifically, these vaccines are based on the vaccinia virus and were first developed against smallpox.

They note that the current monkeypox virus has different genetic variations compared with variants that experts have observed in the past. These variations might impact the efficacy of available vaccines.

The researchers utilized 513 monkeypox complete genome sequences in their research as well as immunological data to predict the potential immune response and vaccine effectiveness against monkeypox.

The results suggest that currently available vaccines, including the MVA-BN and ACAM2000 vaccines, will likely produce an effective immune response to monkeypox.

In the study paper, the authors write that they “report data that anticipates immune responses induced by VACV-based vaccines, including the currently available MVA-BN and ACAM2000 vaccines, to remain highly cross-reactive against the newly observed monkeypox viruses.”

Dr. Arturo Casadevall, an infectious disease expert at John Hopkins University in Baltimore, who was not involved in this research, explained the study concept:

“It is an analysis of 513 monkeypox sequences using computer algorithms to infer likely immunological cross-reactivity, and they deduce that the available vaccinia virus vaccine has a high likelihood of protecting against those strains. Overall the results are reassuring and consistent with what is known.”

There were several limitations to the study. First, based on the methods used, there will need to be experimental studies that confirm the findings. Further data may also differ when it comes to the T-cell response.

Dr. Casadevall noted the following limitations of the study as well:

“As the authors acknowledge in the paper, one limitation of this study is that it is all sequence analysis without concomitant immunological assays. Note that the authors use the word ‘expected’ in the title. Hence, while the results are reassuring, one would need additional immunological studies and/ or clinical evidence to be more confident that vaccinia virus vaccines protect against all strains of monkeypox.”

Currently, the CDC only recommends vaccination for certain at-risk people and groups rather than a broader vaccination rollout. For example, they suggest that those who have been in close contact with someone with monkeypox receive a vaccine.

These recommendations could change as more data emerge about vaccine effectiveness and who is at risk of infection. Vaccines may be available through local health departments, public clinics, and hospitals.

However, the data from this study are encouraging because they indicate that currently available vaccines will elicit an adequate response.

Study authors Prof. Matthew McKay and Dr. Ahmed Abdul Quadeer noted the following to Medical News Today:

“Our data further supports the use of the vaccines that are being recommended globally for combatting the emerging monkeypox outbreak. Clinical evaluations that determine the precise efficacy are still required.”