If it was as simple as that.
If anyone reads the FT.
"The Association of the British Pharmaceutical Industry and the BioIndustry Association said that Europe’s ability to manage big public-health crises related to the use of medicines, such as the Zika virus, could be at risk if the UK were excluded from cross-EU incident management planning."
A report commissioned by the associations suggested that “delays in communication around crisis management or divergence in standards and procedures” between Europe and the UK “are likely to lead to delays in action”.
"there could be a delay of several months in sharing information about drug safety or adverse medical events."
Yes, Im sure emails will stop working post Brexit!