Coronavirus Vaccine

Coronaviruses (CoVs) are a group of viruses that cause the common cold or viral pneumonia that can spread from animals to humans and can spark an outbreak. In early January 2020, Chinese officials and the World Health Organization confirmed over 7,700 cases of the mysterious illness due to coronavirus. The National Institutes of Health (NIH) and other organizations have begun work to develop a vaccine for this new strain of coronavirus, which is also known as 2019-nCoV or COVID-19.

Here is what you need to know about Coronaviruses:

  • What Are Coronaviruses?
  • What Are Human Coronaviruses?
  • What Is Novel Coronavirus (COVID-19)?
  • Where Did the New Coronavirus Come From?
  • How Long Is the Incubation Period for COVID-19?
  • Available Coronavirus DNA Vaccine
  • Is There Any Available Vaccine for New Strain (2019-nCoV)?
  • What Are the Stander Recommendations for the General Public?

Coronaviruses

What Are Coronaviruses?

Coronaviruses are a group of viruses that can cause diseases both in mammals and birds. Most coronaviruses are not dangerous. In humans, these viruses cause respiratory infections. These infections are typically mild, including the common cold, but rarer forms like Severe Acute Respiratory Syndrome (SARS) and Mild East Respiratory Syndrome (MERS) can be lethal.

Coronaviruses were first identified in the 1960s. The earliest ones were discovered in chickens and from the nasal cavities of human patients (1).

The name “coronavirus” was derived from the Latin word “corona” meaning crown or halo. The crown refers to the characteristic appearance of a virus having a fringe of large, bulbous surface projections, which creates an image reminiscent of a royal crown.

Image: Renders of 2019 Novel Coronavirus (2019-nCoV) Adapted from Public Health Image Library (PHIL)

 

What Are Human Coronaviruses?

In human adults and children, “Human Coronaviruses” are considered to cause a significant percentage of all common colds.

In humans, Coronaviruses cause colds primarily in the winter and early spring seasons with major symptoms, e.g., fever, swollen throat adenoids (2).

Moreover, Coronaviruses can cause pneumonia, either direct viral pneumonia or secondary bacterial pneumonia. They can also cause bronchitis (cough), either direct viral bronchitis or secondary bacterial bronchitis.

In 2003, a much-publicized human coronavirus discovered that known a SARS-CoV. It causes severe acute respiratory syndrome (SARS).

It has unique pathogenesis because it causes both upper and lower respiratory tract infections.

There are a total of seven strains of human coronaviruses as described in the table below;

CategoryStrainsDiscovery
 

Common Human Coronaviruses

Human coronavirus 229E1965
Human coronavirus NL632004
Human coronavirus OC432000
Human coronavirus HKU1January 2005
 

Other Human Coronaviruses

Middle East respiratory syndrome coronavirus (MERS-CoV)2012
Severe acute respiratory syndrome (SARS-CoV)November 2002
Novel coronavirus (2019-nCoV)January 9, 2020

Table: 7-strains of human coronaviruses [Adapted from the Center for Disease Control and Prevention (CDC)]

 

What Is Novel Coronavirus (COVID-19)?

In December 2019, a pneumonia outbreak was reported in Wuhan, China (3). The outbreak was traced to a unique strain of coronavirus, on 31 December 2019. World Health Organization labeled this virus as 2019-nCoV.

Image: 2019 Novel Coronavirus (2019-nCoV) [Adapted from Public Health Image Library (PHIL)]

By 29 January 2020, more than 130 deaths had been reported, and more than 6,160 confirmed cases in this coronavirus pneumonia outbreak.

Daniel Lucey, an infectious disease specialist at Georgetown University, stated that the first human infections must have occurred in November 2019 and maybe earlier (4).

 

Where Did the New Coronavirus Come From?

The virus was suspected of having originated in snakes. But many other leading researchers disagree with this statement. Daniel Lucey stated that “Now it seems clear that the seafood market is not the only origin of the virus”.

 

How Long Is the Incubation Period for COVID-19?

It depends on different people. Chinese scientists estimated the incubation period for COVID-19 may range from 1 to 14 days.

 

Available Coronavirus DNA Vaccines

World Health Organization (WHO) blueprint aims the development of two types of human Middle East respiratory syndrome (MERS) coronavirus vaccines for long-term protection of people at high exposure risk and reactive use in outbreak settings (5).

Kayvon Modjarrad and his colleagues have developed phase 1, open-label, single-arm, first-in-human evaluation of the Middle East respiratory syndrome (MERS) coronavirus DNA vaccine.

This coronavirus DNA vaccine was well tolerated with no vaccine-associated serious adverse events.

Besides this, no licensed MERS coronavirus vaccine is currently available; because of substantial challenges exist to the development of such a vaccine. These are;

  • The available animal models (e.g., rhesus macaques, transduced mice, transgenic mice, rabbits, marmosets, alpacas, and camels) might not mimic human disease (6).
  • Immune protection has not been well defined. The protective immune response in natural infection is also poorly understood, although both humoral and cellular responses are probably necessary for viral clearance (7).
  • There is a theoretical risk of immune enhancement during MERS coronavirus infection after vaccination, possibly leading to lung immunopathological (8).
  • If MERS shifts from a pattern of sporadic outbreaks to pandemic spread, it is not known whether vaccines based on current MERS coronavirus isolates will offer protection against pandemic strains.

Is There Any Available Vaccine for New Strain (2019-nCoV)?

Since 2003, the world has suffered three significant outbreaks that induced by coronaviruses, including Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and now the prevailing epidemic caused by a virus known as a novel coronavirus (2019-nCoV).

Once the viruses start infecting humans, the work on vaccines for severe coronaviruses has historically started

The National Institutes of Health (NIH) and other organizations have also begun work to develop a vaccine for this new strain of coronavirus, which is also known among scientists as 2019-nCoV (9).

Scientists are just getting started working. Their vaccine development strategy will help not only closely related viruses, such as SARS and MERS but also the progressions that have been made in vaccine technologies, such as nucleic acid vaccines. These vaccines are DNA- and RNA-based vaccines that produce the vaccine antigen in your own body (10) (11).

The mRNA vaccine can be made quickly. It could be rapidly developed as it does not need to be grown in chicken eggs, as is the flu vaccine, for instance. A company in the Boston area is already working on designing an mRNA vaccine based on the genetic sequence of the new coronavirus strain released by the Chinese government this month.

Initial trials in people imply that such a vaccine can significantly stimulate an immune response, but it has never been examined during an outbreak.

Chinese scientists found that Chinese medicine called Shuanghuanglian has an effect on inhibition of the novel coronavirus (2019-nCoV).

How Do mRNA Vaccines Work?

Experts design an mRNA vaccine to carry information for making the same proteins that found on the outside of a particular type of virus. In this case, the new coronavirus. These proteins stimulate the body’s immune system to make antibodies against that virus, and therefore to be able to fight off any actual infection from that virus.

National Institute of Health (NIH) officials say: advances in technologies since the SARS outbreak have significantly compressed the vaccine development timeline. A candidate vaccine for the novel coronavirus (2019-nCoV) could be ready for early-stage human testing in as little as three months (12)

All early indications of the mRNA approach are positive. In seven clinical trials, roughly 1,000 people have received different versions of mRNA vaccines designed to prevent other respiratory viruses, including human metapneumovirus (HMPV), a strain of the flu, and respiratory syncytial virus (RSV).

The vaccine seemed to produce a strong immune response equivalent to one in people who had recovered from the virus.

 

What Are the Stander Recommendations for the General Public?

The best protection remains frequent hand-washing until a safe and effective vaccine can be developed. The CDC recommends hand-washing, scrubbing hands for at least 20 seconds after lathering (13).

To reduce exposure to and transmission of a range of illnesses, the World Health Organization’s standard recommendations for the general public are as follows;

  • Regularly disinfect your hands by using alcohol-based hand rub or soap and water.
  • When sneezing or coughing, cover your mouth and nose with flexed elbow or tissue. Throw the tissue aside immediately and wash your hands.
  • If you have a fever, cough, and difficulty breathing, ask medical care early, and share prior travel history with your health care provider.
  • Close contact with anyone who has a fever and cough should be avoided.
  • Avoid direct unprotected contact with live animals and surfaces in contact with animals when visiting live markets in areas currently experiencing cases of a novel coronavirus.
  • Handel raw meat, milk, or animal organs with care as per good food safety manners to avoid cross-contamination with uncooked food.

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