4.3.3. Nanotechnology-based Approaches to Manage COVID-19
Along with the efforts made in the field of discovering and developing various types of drugs through different approaches, adopting a multidisciplinary perspective by making use of nanomaterials in the field of detection and diagnostics, drug delivery, protective equipment, and other preventive strategies can prove to be helpful. Real-Time-Polymerase Chain Reaction (RT-PCR) is the widely used diagnostic method for detecting COVID-19 and this process can be made less labor-intensive and less time-consuming by using nanoparticles in the viral extraction procedure. Nanoparticles can help to upregulate the immune response against the antigen and also in increasing the specificity of the immune response by directing the antibodies towards the specific antigen. Silver or gold nanoparticles are widely used in point of care devices where the viral antigen binds to these nanoparticles and this binding produces a detectable change of color. Nanobiosensors have been developed which can rapidly detect SARS-Cov-2 with good accuracy and cost effectivity.
Nanotechnology-based solutions can be used to develop highly efficient anti-viral coatings which can further be used in the making of personal protective equipment and face masks, for example, nanofibers developed using copper oxide and graphene oxide can inactivate virus particles and can be incorporated into face masks. The scope of the application of nanoparticles in the health sector does not end here. By bringing together the conventional antiviral modalities along with the advantages of nanoscale particles, it is possible to improve detection and treatment methods, thereby helping in improving the COVID-19 management strategy.  The applications of nanotechnology in the effective management of COVID-19 are shown in Figure 8 . There has been a substantial amount of research performed on efficient drugs against COVID-19, and a comparison of the efforts put into finding chemical drugs, phytochemical drugs, and nanotechnology-based approaches in the last 5 years is shown in Figure 3B .
CURRENT ADVANCES IN VACCINE DEVELOPMENT
Besides the aim of developing effective drugs to treat COVID-19, efforts have also been made to develop promising vaccines that can boost immunity and control viral infection. The process of development of the various vaccines that are available now or those that are under trial has occurred at such an accelerated rate that we now have over 184 vaccine candidates in their preclinical development stage and over 100 vaccine candidates undergoing clinical trials. Of these, almost fifty are undergoing human experimentation and some of them have also been approved for administration. There are mainly 4 types of COVID-19 vaccines- 1) whole virus vaccine 2) protein-based vaccine 3) viral vector vaccine and 4) nucleic acid vaccines. All vaccines that are presently in the trial are injected vaccines, however, to control an infection that mainly starts in the nasopharynx, nasal vaccines may prove to be more helpful. Lyophilized vaccines can be administered intranasally if it has good aerosol properties. Recently, The Bharat Biotech has developed a one drop nasal vaccine against SARS-CoV-2, named “CoroFlu”, and it is presently in the animal trials stage. A brief description of some of the vaccines currently in phase 3 (humantrials) and phase 4 (post-marketing surveillance) study are mentioned inTable 3 . The different vaccines that are currently in use are summarized in Table 4.
The COVID-19 vaccines currently in use have shown good efficiency and it was seen that it reduced COVID-19 hospitalizations and ICU admissions as well as deaths. However, these benefits don’t come without risks. The reported side effects of the mRNA-based vaccines in use so far include fever, redness, swelling, injection site pain, myalgia, arthralgia, induration, pruritus, chills, vomiting, fatigue, and headache. It was also reported that the adenovirus-vectored vaccine was associated with higher rates of diarrhea and arthralgia. Extreme and severe side effects have been rarely reported and those that have been reported do not have any evidence to direct the cause to the vaccine. The relatively rapid and successful development of the vaccines against COVID-19 is to be truly appreciated, however, with the evolving virus, it is equally important to take up an evolving vaccine approach, where vaccines need to be continuously modified to maintain their efficiency.
RISKS OF COVID-19