The vaccine is given by intramuscular injection. It is composed of nucleoside-modified mRNA (modRNA) encoding a mutated form of the full-length spike protein of SARS-CoV-2, which is encapsulated in lipid nanoparticles. Vaccination requires two ...
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COVID-19's caused virus, SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), was isolated in late 2019. Its genetic sequence was published on 11 January 2020, triggering an urgent international response to prepare for an outbreak ...
- Side Effects and Risks
- Vaccine Hesitancy
- Efficacy of mRNA Vaccines For Covid-19
- Self-Amplifying RNA
- See Also
- Further Reading
In 1989, the first successful transfection of mRNA packaged within a liposomal nanoparticle into a cell was published. In 1990, "naked" (or unprotected) mRNA was injected into the muscle of mice. These studies were the first evidence that in vitrotranscribed mRNA could deliver the genetic information to produce proteins within living cell tissue. In 1993, liposome-encapsulated RNA was shown to stimulate T-cellsin vivo, and in 1994, RNA proved useful as a vaccine to elicit both humoral and cel...
In 2005, successful application of modified nucleosides as a medium to get mRNA inside cells without setting off the body's defense system was reported. In 2010, the mRNA-focused biotechnology company, Moderna, was started to develop mRNA biotechnologies. In 2010, US government agency DARPA launched a biotech research program called ADEPT as part of its mission to develop emerging technologies for the US military. In 2011, DARPA recognized the potential of nucleic acid technology for defense...
In December 2020, Moderna and BioNTech obtained FDA emergency use authorization for their mRNA-based COVID-19 vaccines, which had been funded by Operation Warp Speed. On 2 December 2020, seven days after its final eight-week trial, the UK's Medicines and Healthcare products Regulatory Agency (MHRA), became the first global medicines regulator in history to approve an mRNA vaccine, granting emergency authorization for Pfizer–BioNTech's BNT162b2 COVID-19 vaccine for widespread use. On 11 Decemb...
The goal of a vaccine is to stimulate the adaptive immune system to create antibodies that precisely target that particular pathogen. The markers on the pathogen that the antibodies target are called antigens. mRNA vaccines operate in a very different manner from a traditional vaccine. Traditional vaccines stimulate an antibody response by injecting antigens, an attenuated virus (weakened or harmless virus), or a recombinant antigen-encoding viral vector (carrier virus engineered to have antigens) into muscles. These antigen-containing ingredients are prepared and grown outside the body. In contrast, mRNA vaccines introduce a short-lived synthetically created fragment of the RNA sequence of a virus into the vaccinated individual. These mRNA fragments are taken up by dendritic cells – a type of immune system cell – by phagocytosis. The dendritic cells use their own internal machinery (ribosomes) to read the mRNA and produce the viral antigens that the mRNA encodes be...
The method of vaccine delivery can be broadly classified by whether the RNA transfer to cells happens within (in vivo) or outside (ex vivo) the organism.
Reactogenicity is similar to that of conventional, non-RNA vaccines. However, those susceptible to an autoimmune response may have an adverse reaction to RNA vaccines.The mRNA strands in the vaccine may elicit an unintended immune reaction, your body thinks its sick and acts like it. To minimize this, mRNA sequences in mRNA vaccines are designed to mimic those produced by host cells. Strong but transient reactogenic effects were reported in trials of novel COVID-19 RNA vaccines; most people will not experience severe side effects which include fever and fatigue. Severe side effects are defined as those that prevent daily activity.
RNA vaccines offer specific advantages over traditional protein vaccines. Because RNA vaccines are not constructed from an active pathogen (or even an inactivated pathogen), they are non-infectious. In contrast, traditional vaccines require the production of pathogens, which, if done at high volumes, could increase the risks of localized outbreaks of the virus at the production facility. RNA vaccines can be produced faster, more cheaply, and in a more standardized fashion (with fewer error ra...
In addition to sharing the advantages of theoretical DNA vaccines over established traditional protein vaccines, RNA vaccines also have additional advantages over DNA vaccines. The mRNA is translated in the cytosol, so there is no need for the RNA to enter the cell nucleus, and the risk of being integrated into the host genome is averted. Modified nucleosides (for example, pseudouridines, 2'-O-methylated nucleosides) can be incorporated to mRNA to suppress immune response stimulation to avoid...
There is misinformation implying that mRNA vaccines could alter DNA in the nucleus. mRNA in the cytosol is very rapidly degraded before it would have time to gain entry into the cell nucleus. (mRNA vaccines must be stored at very low temperature to prevent mRNA degradation.) Retrovirus can be single-stranded RNA (just as SARS-CoV-2 vaccine is single-stranded RNA) which enters the cell nucleus and uses reverse transcriptase to make DNA from the RNA in the cell nucleus. A retrovirus has mechanisms to be imported into the nucleus, but other mRNA lack these mechanisms. Once inside the nucleus, creation of DNA from RNA cannot occur without a primer, which accompanies a retrovirus, but which would not exist for other mRNA if placed in the nucleus.Thus, mRNA vaccines cannot alter DNA because they cannot enter the nucleus, and because they have no primer to activate reverse transcriptase. In November 2020, The Washington Postreported on novel mRNA vaccine hesitancy amongst healthcare profes...
It is unclear why the novel mRNA COVID-19 vaccines from Moderna and Pfizer–BioNTech have shown potential efficacy rates of 90 to 95 percent when the prior mRNA drug trials on pathogens other than COVID-19 were not so promising and had to be abandoned in the early phases of trials. Physician-scientist Margaret Liu stated that it could be due to the "sheer volume of resources" that went into development, or that the vaccines might be "triggering a nonspecific inflammatory response to the mRNA that could be heightening its specific immune response, given that the modified nucleoside techniquereduced inflammation but hasn't eliminated it completely", and that "this may also explain the intense reactions such as aches and fevers reported in some recipients of the mRNA SARS-CoV-2 vaccines". These reactions though severe were transient and another view is that they were believed to be a reaction to the lipid drug delivery molecules. Unlike DNA molecules, the mRNA molecule is a very fragile...
Self-amplifying RNA (saRNA) is a technology similar to mRNA, except the saRNA produces multiple copies of itself in the cell before producing proteins like mRNA does. This allows smaller quantities to be used and has other potential advantages. saRNA vaccines are being researched, including development of a malaria vaccine.
Sahin U, Karikó K, Türeci Ö (October 2014). "mRNA-based therapeutics--developing a new class of drugs". Nat Rev Drug Discov. 13 (10): 759–80. doi:10.1038/nrd4278. PMID 25233993.
National regulatory authorities have granted emergency use authorizations for twenty-one COVID-19 vaccines.Six of those have been approved for emergency or full use by at least one WHO-recognized stringent regulatory authority ...
- Vaccine Orders and Arrival
On 3 March 2021, the first shipment of the Oxford–AstraZeneca COVID-19 vaccine was delivered. The 117,000 doses are part of the 10 million doses of the vaccine that the Taiwanese government had previously ordered. On 18 March 2021, the AstraZeneca vaccine was approved by the government, and vaccinations commenced on 22 March 2021. The vaccine is free for all Taiwanese people and long-term residents.Health workers, other frontline workers and seniors were the first to be inoculated with the vaccine. On 5 May 2021, the Moderna COVID-19 vaccine was approved for emergency use,and the first batch of 150,000 doses was delivered on 28 May 2021. On 17 May 2021, 400,000 doses of the AstraZeneca vaccine that were ordered through COVAX arrived in the midst of Taiwan's largest COVID-19 pandemic. On 31 May 2021, Taiwan Centers for Disease Control announced that 10 million doses of domestically produced vaccines (Medigen and United Biomedical) had been pre-reserved. 5 million of each vaccine were...
The Taiwanese government has ordered COVID-19 vaccines directly from the Oxford-AstraZeneca, Moderna, Medigen Vaccine Biologics Corp., and United Biomedical. The Taiwanese government has also ordered another 4.76 million dose of vaccine through the COVAX platform besides the direct orders from pharmaceutical companies. An additional 15 million doses of Pfizer-BioNTech COVID-19 vaccine purchased by Foxconn, Taiwan Semiconductor Foundry Company, and Tzu-Chi Foundationwere also been donated to t...
The Taiwanese government has created a prioritization list for domestic COVID-19 vaccination plan, which includes 10 prioritized groups.
Vaccination Appointment Platform
On 6 July, the Central Epidemic Command Center (CECC) announced the creation of Taiwan Domestic COVID-19 Vaccination Appointment Platform, allowing the digitalization of COVID-19 vaccination sign up and appointments. The platform was created to simplify vaccination appointments and increase vaccine roll-outs. The platform is a four-step system. In the first step, individuals would need to sign up on the website and fill in the necessary information, such as their National Identification Card...
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- External Links
In February 2016, a Nature editorial criticized Moderna for not publishing any peer-reviewed papers on its technology, unlike most other emerging and established biotech companies, and compared its approach to that of the controversially failed Theranos. In September 2018, Thrillist published an article titled, "Why This Secretive Tech Start-Up Could Be The Next Theranos", criticizing its reputation for secrecy and the absence of scientific validation or independent peer-review of its research, though having the highest valuation of any U.S. private biotech company at more than $5billion. A former Moderna scientist told Stat: "It's a case of the emperor's new clothes. They're running an investment firm, and then hopefully it also develops a drug that's successful."
Taiwan Centers for Disease Control. The COVID-19 pandemic in Taiwan is part of the worldwide pandemic of coronavirus disease 2019 ( COVID-19) caused by severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ). As of 25 July 2021, 3,506,490 ...