Zika Virus History and Potential Vaccines

For the most phase of the twentieth century, Zika virus was widely unknown and as different severe mosquito-borne viruses such as dengue and chikungunya attracted more interest. In the recent years, however, the world has been hit by outbreaks after outbreaks of the viruses in special locations and the quiet disease turning into more impactful that previously imagined. Moreover, the virus has been linked with baby microcephaly and temporary paralysis, putting the world on excessive alert on potential outbreak zones. The World Health Organization responded to the Zika virus outbreak by means of placing its outbreaks under a “public fitness emergency of international concern.
To understand the disorder and how it works, scientists are scrambling on knowledge about the virus discovery and history of its spread. They hope that through such studies, they can produce an effective treatment and maybe a potential cure for Zika virus. Due to the rapid increase in focus on the disease, the Zika virus science is changing fast. This report discusses the history of the virus, the prevention measures, and the potential vaccines suggested by scientists.

History

Zika virus was initially discovered in 1947, during a routine surveillance for yellow fever by Uganda Yellow Fever Research Institute scientists’ in Uganda’s Zika forest (Medical Daily, 2016). The forest was a potential research area due to its tropical nature that encompassed diverse ecosystems, mosquitos included. Afterward, the scientists were able to isolate the virus from a rhesus monkey that was captured in the forest for its first study.

In 1948, an Aedes africanus mosquito was captured in the Zika forest and the virus extracted from it. It was not until 1952 that the researchers were able to identify the first human infection of the disease; cases were reported in Uganda and Tanzania. After further studies, more strains of the Zika virus were discovered by 1958 from the same Aedes Africanus mosquito (Medical Daily, 2016).

When David Simpson, a researcher working with the Zika strains in Uganda fell ill from the virus in 1964, he published an observational study of the infection. He noted that the ”clinical picture of the infection was that of a mild febrile illness of short duration accompanied by a generalized maculopapular rash (Medical Daily, 2016).” In addition to that, he explains that ”a rise in antibody to Zika virus was demonstrated (Medical Daily, 2016).” This was the first published proof that the Zika virus was capable of causing human diseases.

Notably, at those times, the Zika virus was mentioned in the same breath as chikungunya and dengue fevers, both of which were transmitted through mosquitos, but milder. In the next few decades, the Zika virus spread and was reported in other areas such as Pakistan, India, Malaysia, and Indonesia (Medical Daily, 2016). Although cases of infections were reported, there was no outbreak reported, and the disease continued being regarded as a mild virus. Through studies, the scientist believes that the similarities illness and Chikungunya and dengue were the main reason as to why its cases were rarely reported, with only 14 cases reported.

Having been a quiet disease, in 2007, Zika virus made a comeback and caused an outbreak on Yap Island in the Caroline Islands. At the time, the outbreak was pinned on the travelers who traveled overseas via infected locations. Six years later, in 2013, another epidemic was reported in New Caledonia, Cook Island, Easter Islands, French Polynesia and other Pacific Islands. This was the genesis of the intense studies of the disease and discovery of probable linkage between the virus and other chronic consequences like autoimmune complications, Guillain-Barré syndrome, and most commonly, microcephaly.

In 2nd March the same year, several states in Brazil reported cases of mysterious illness that caused rushed to appear on the body. However, the doctors tested for chikungunya, dengue, measles as well as rubella as they did not anticipate an onset of Zika virus in the locality. By April the same year, more than 7000 cases had been reported. As the disease continued spreading, on 7th May 2015, WHO declared an alert to Zika virus infection (The Pharmaceutical Journal, 2016).

Unexpectedly, scientist, discovered that there was a clear connection between Zika virus and microcephaly and the Guillain-Barré syndrome; this was later in April 2016 confirmed by WHO (Hajra, Bandyopadhyay, & Hajra, 2016). As the cases of the disease spread, reported in January 2016 in Puerto Rico, the CDC began outlining travel guidelines and warnings to pregnant women to get away from the infected areas. With a different outbreak, the disease was changing form and pattern. It expanded geographically leading to larger and larger outbreaks.

Discussion

Prevention of Zika Virus

There is no cure available for Zika virus, and preventive measures are the only sure way of keeping away from the disease (Hajra, Bandyopadhyay, & Hajra, 2016). In addition to that, there is no anti-viral medication confirmed to deal with the virus and eliminate it from the body, making the immune system the only best fighter of the disease. Just as dengue and chikungunya, the Zika virus requires a comprehensive approach to the completely deal with the disease: This include health advice and public education.

Zika virus is carried and spread by Aedes Africanus mosquito. This means that one of the sure ways of keeping Zika virus from spreading is by ensuring that human contact with mosquitoes is minimized or completely avoided (Zikavirusnet.com, n.d.)This can be done using two methods: controlling the larvae or adult mosquito and reducing the exposure to mosquito bites during daylight hours.

To control the larvae and adult mosquitoes, the best practice is eliminating their breeding sites. Any arterial containers to natural pools need to be drained and reduce the breeding grounds and ensure that any larvae are killed (Chiodini, 2017). More so, larvicide treatment presents another way of eliminating the larvae in the water collections points around the compound. Investing in insect growth regulators is also a better way of ensuring that the larvae do not grow into mosquitoes. Other activities that involve eliminating water collection points hence eliminating the potential breeding zone (Chiodini, 2017). These include plastic cups, broken vases, papers and other polyether papers.

To reduce the exposure to mosquitoes can present a way out of contracting Zika virus. Lessen the exposure to mosquito means reducing the chances of getting bitten and infected with the virus (PAHO & WHO, 2016). The best technique to do this is by applying mosquito repellents. Repellents such as DEET, Picaridin, and Oil of lemon eucalyptus repel the number of mosquitos that can land on the body. These repellents block the mosquito’s ability to spot one and with a limited amount of time, keeps the person safe from mosquito bites.

As an effort to fight the virus, CDC laid down guidelines for pregnant women (CDC, 2017). They suggested that any pregnant woman on the verge of visiting Zika-affected regions should consult their doctors for further instruction. In addition to that, the CDC provide a detailed guideline that the mother and the infant need to visit the clinic after that visiting any county red flagged for Zika.

The CDC also laid down the biosafety guideline in handling, transportation, and studying of Zika virus specimen. The transport of the virus is monitored under the Category B Biological Substance while under transportation (CDC, n.d.). Also, the importation of the specimens requires a CDC import permit and the USDA permit. Before handling the sample, the CDC recommends that the Biosafety Level 2 precautions that require one to wear gloves, a lab court, and eye protection.

Finally, the WHO in conjunction with Pan American Organization (PAHO) supported the guidelines proposed by CDC. They, however, added the guidelines requirement for those who are planning to have children and are living in the potential zika red zones should take all the necessary precautions (Citil Dogan et al., 2016). They should visit the hospital and comply with the recommendation of their health officers. Lastly, the pregnant women with partners coming from areas with Zika virus outbreaks should use protection to ensure safer sex until the child is born; if possible, avoiding sex altogether is recommended.

Potential Vaccines

Much effort has been dedicated to the advance of the Zika vaccine, with at least 40 entities working to produce vaccine candidates. Which each researcher is utilizing a given platform, the goal is to produce the best vaccine that will fight the virus and provide immunity to the human being (Barrett, 2016). The platforms used include recombinant envelope (rE) protein, purified formalin-inactivated virus adjuvanted with alum (PIV), DNA vaccines, the VLP Vaccines, Recombinant chimeric live vaccines, and purified inactivated virus vaccines, recombinant subunit vaccines, and the virus vectored vaccines.

Live attenuated vaccines (LAV) can offer protective immunity after one of a few doses. While in the body, the vaccine multiplies in the host and stimulates the B and the T cells (Dawes et al., 2016). Recently, a chimeric recombinant LAV for Japanese encephalitis (JEV) and dengue was licensed. This gives hope for the Zika virus LAV to be approved too.

In the same manner, Inactive flavivirus vaccines have been licensed for JEV (Dawes et al., 2016). This vaccine requires one to receive multiple doses that include a high virus titer of protein for the introduction of a protective immune response.

Though the stage of developments is ongoing for non-replicating, subunit flavivirus, none has been approved in any other field including the Japanese encephalitis (JEV) or dengue (The Pharmaceutical Journal, 2016). If successfully produced, the recombinant subunit can provide vaccines with a robust immunity, especially towards specific antigenic epitopes.

Conclusion

As the world turns its attention towards combating Zika virus, people need to do their part and follow the necessary guidelines placed by bodies such as the CDC and the WHO. By ensuring that people keep mosquitos away from their household and that pregnant women keep of Zika outbreak zones, the number of cases of infection will reduce tremendously. The efforts that are laid down by the researchers and scientists are meant to produce a vaccine that will immune the system against the Zika virus. Finally, the approval of these vaccines may compliment the efforts to keep mosquito away and lead to the elimination of Zika as a virus.

References

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Chiodini, J. (2017). ‘Preventing the Zika virus: Understanding and controlling the Aedes Mosquito’ – A free online course. Travel Medicine And Infectious Disease. http://dx.doi.org/10.1016/j.tmaid.2017.01.002

Citil Dogan, A., Wayne, S., Bauer, S., Ogunyemi, D., Kulkharni, S., & Maulik, D. et al. (2016). The Zika virus and pregnancy: evidence, management, and prevention. The Journal Of Maternal-Fetal & Neonatal Medicine, 30(4), 386-396. http://dx.doi.org/10.3109/14767058.2016.1174210

Dawes, B., Smalley, C., Tiner, B., Beasley, D., Milligan, G., & Reece, L. et al. (2016). Research and development of Zika virus vaccines. Npj Vaccines, 1, 16007. http://dx.doi.org/10.1038/npjvaccines.2016.7

Hajra, A., Bandyopadhyay, D., & Hajra, S. (2016). Zika virus: A global threat to humanity: A comprehensive review and current developments. North American Journal Of Medical Sciences, 8(3), 123. http://dx.doi.org/10.4103/1947-2714.179112

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PAHO & WHO,. (2016). Zika Virus Infection. Step-by-Step Guide to Risk Communication and Community Engagement. Iris.paho.org. Retrieved 7 February 2017, from http://iris.paho.org/xmlui/handle/123456789/33670

Stawicki, S., Sikka, V., Chattu, V., Popli, R., Galwankar, S., & Kelkar, D. et al. (2016). The emergence of zika virus as a global health security threat: A review and a consensus statement of the INDUSEM Joint working Group (JWG). Journal Of Global Infectious Diseases, 8(1), 3. http://dx.doi.org/10.4103/0974-777x.176140

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